Method and apparatus for synchronizing two or more disconnected elements



May 27, 1930. H. J. NICHOLS 1,759,354

METHOD AND APPARATUS FOR SYNCHRONIZING TWO OR MORE DISCONNEGTED ELEIBNTS Filed Jan 10, 1923 2 Sheets-Sheet l POmTlNG D! 60 .i

To oemowe 615T CONTACT 8 CON TA 0 TOR 3 A 03 semome STATION POTATING D150 7 SIGHT HOLE a 7-?ED LIGH T T 1 SET WHITEUGHT. GTATIONARV6 ORECE/VNG 6 GREEN LIGHT B o or? RECEIVING \S'TAWQN Shown,

May 27, 1930. NlcHoLs 1,759,864

METHOD AND APPARATUS FOR SYNCHRONIZING TWO OR MORE DISCONNECTED ELEMENTS Filed Jan- 10, 1925 2 Sheets-Sheet 2 POTATING 313150 7 76 RECEIVING SET 6 IND/CATING LAMP BOR RECEIVING ,SFATI ON /0 i TO FECEII/ING SE) a MOTOR 1 ,SELEiV/l/M PLATE 11 Jnucntoz HllNichoLs Patented May 27, 1930 UNITED STATES PATENT OFFICE HARRY J. NICHOLS, OF WASHINGTON, DISTRICT 0] COLUMBIA HETHOD AND APPARATUS FOR SYNCHBONIZING TWO OR MORE DISGONNEGTED ELE- MEN'I'B Application filed January 10, This invention relates to the method of and movements of apparatus for synchronizing two or more disconnected elements.

The method is particularly intended to be applied to the synchronization of two rotatable members employed at the sending and receiving stations respectively in the transmission of photographs by radio and in the following description the invention will be described with relation to such application although it is, of course, to be understood that without material modification the apparatus and method are applicable to other purposes.

In order that a clearer present invention and the objectssought to be accomplished thereby ma be had, it is to be stated that in the transmlssion of photographs by radio, in one method now employed, it is necessary to synchronize the motor driving the rotary disc-prisms or equivalent devices used in transmitting the photographic signals with the motor which drives similar rotary disc-prisms b which the photographic signals are repro need as photographs. Heretofore in order to accomplish this synchronization it has been the practice to connect the prism driving motors at the sending and receivin station to the same electrical circuit of uni orm frequency, as for instance to the public utility power system, whereby the synchronization of the motors was efl'ected. It is therefore one of the purposes of this invention to obviate the necessity of so connecting the motors and to have them independent as to source of power and synchronized by radio communication from the sending to the receiving station.

A further object of this invention is to provide a method and means for synchronizing both as to time and phase two or more mechanisms which are remotely situated from each other. The mechanisms which are to be synchronized may consist of revolving elements, oscillating elements, or others of definite periodicity.

A further object is to practical mechanism which will be either manually operated or automatic in its operation to positively and accurately synchronize perception of the provide a simple and 1823. Serial No. 811,828.

two relatively remote and physically disconnected elements.

Other objects will be in art obvious and in part hereinafter pointed out in connection with the following description taken in connection with the accom anying sheets of drawings forming part of t is disclosure and illustrating two of various modifications of apparatus in which igure 1 shows a schematic diagram of the or sending station omitting the details of the radio sending equipment, which may be of any suitable type or construction.

Figure 2 is a similar diagram of the B or receiving station.

Figures 3 and 4 are diagrams illustrating the method of obtaining automatic synchronization by means of a light reactive device such as a selenium resistance plate.

The elements of the A or sending station are as follows: A rotating disc 1 carries a contact 2 which periodically makes contact with a contactor 3 thereby transmitting periodic electrical impulses to a sending set 4 which broadcasts a corresponding signal or wave impulse at any desired wave length or frequency.

The B or receiving station consists of the usual receiving set having an auxiliary circuit 5 connected with a source of radiant energy such as light emitting elements or lamps 6 so as to make visible the periodic signals received from station A; and thrrotating disc 7 which it is desired to synchronize with disc 1 of station A.

The rotating disc 7 should be made of lamp.

The operation of this device is as follows: For each revolution of the disc 1 a brief signal is sent out from the sending station A.

ese signals are received at the station B and after suitable amplification appear simultaneously as flashes of light in the indicating lamps 6, the flashes therefore having the same frequency as the disc 1 has revolutions.

If the disc 7 is then regulated to rotate so that the sight'hole 8 is ust over the white lamp each time it flashes, the white light will be seen continuously or intermittently, depending on the frequency of the flashes, and the disc 7 will be rotating exactly at the same rate as the disc 1, or the speed of one disc is an exact multiple of the ot er. It is assumed that in practice the receiving station will know the approximate speed of rotation of the disc 1 at t e sending station A and that the usual forms of tee ometers may be used to accomplish the approximate synchronization of the discs, while the method herein described may be used to accomplish their exact synchronization.

If, after the discs are synchronized with the white light showing, the speed of the disc 1 increases, or the speed of the disc 7 decreases, the red sector will be gradually uncovered so that the white light will change to red. Conversely, if the s eed of the disc 1 decreases or that of disc increases, the green li ht will appear, thus indicating automatica g the manner in which to regulate the spec of the disc 7 to synchronize it again withthe disc 1.

It will be apparent that the same result may be accomphshed by having one stationary indicating lamp and variously colored sectors in the disc 7. Also, various changes and additions might be made to regulate the s eed of the disc 7 automatically to that of t e disc 1, for example One method of obtaining automatic regulation of the s eed of the disc 7 is shown diagrammatica ly in Figures 3 and 4. The rotating disc 7 instead of being furnished with a si ht hole is provided with sectors a, b, an a (three being shown by way 0 illustration) of varying degrees of radiant energy transmitting capacities, the most translucent sector being away from the direction of motion. disc 7 so as to pass directly over a single source of radiant energy such as the lamp 10 similar to those shown in Figure 2. Opposite the indicating lamp 10 is a radiant energy or light re-active device H such as a selenium resistance plate or photo-electric cell so arranged as to receive light passing from the lamp 10 through the translucent sectors in the disc 7. A connecting beam or light link is thus set up, under certain conditions, between the light source 10 and the re-active device 11, the said link being controllable as hereinafter set forth. The light re-active device 11 is part of the speed regulating or control circuit, such as the shunt field circuit of the disc driving motor 12, it being 65. understood that the light reactive device may f land The sectors are located in the res control the driving motor in the manner shown, or by other suitable means as commonlyl practiced such as intermediary relays and t e like.

The operation of the automatic regulator is as follows: The indicating lamp 10 will flash in synchronism with the disc 1 as previously described. If none of the translucent sectors of the disc 7 are op osite the light re-active device 11 when the ight flashes, the connecting light link between the lamp 10 and the re-active device 11 is cut oil by the disc 7, and the re-active device will receive no light, and consequently its resistance will be relatively high. This resistance in the shunt field of the motor 12 will speed up the motor thus correcting by increasing the speed of the disc 7 connected therewith and thereby bring the translucent sector (a) over the I lamp 10 at the time the li ht flashes, to thus complete the light link to t e re-active device 11. The sector (a) will transmit some light to the light re-active device 11 thereby decreasing the s eed of the motor 12; eventuthe disc 7 is brought to the desired speed the sector (12) is over the indicating lamp at the time the light flashes, the motor being normally regulated to give this result. Should the motor now increase its speed to thus cause a departure from the desired synchronous relation, the sector (a) will then pass over the lamp 10 as it flashes, thereby transmitting more light to the light re-active device 11 and decreasing the speed of the motor 12. Thus, the connecting light link is varied or controlled by the disc 7 and/or the sectors (a), (b), and (0), such variation or control thereupon eifecting a control of the rate of movement of the disc 7. Obviously, the disposition and number of sectors, of which three are "shown by way of illustration, is such to initially establish the desired s nchronous relation between the discs and to thereafter maintain the disc 7 in synchonism with the disc 1, it being apparent that as in the previous case, a change in speed of the disc 1 will produce a corndin change in the disc 7.

1: will e seen that the method described can therefore be applied in various ways to accomplish the automatic or manual synchronization of two rotating discs and the method can be applied to other periodic motions by suitable adaptation.

It is further seen that similar methods utilizing radiant energy in any form to secure coo eration of the controlelements may readily e racticed b suitable apparatus following t e method erein disclosed, and all such methods are broadly encompassed in the following claims.

What I claim is z-- 1. In a paratus of the class described, in combination, a sending station, a periodically moving element and means associated therewith for sending an electrical impulse during each period or cycle of movement, a recelving station having an associated circuit which is energized upon the reception of the impulse, a movingele nentatthe receivin station, a source of radiant energy in em circuit, means to control the energy transmitted from the energy source in accordance with the departure of the second element from a m synchronous phase relation with the first element, and means responsive to such control to synchronize the movement of said elements.

2. In apparatus of the class described, in combination, a sending station, a periodically movin element and means associated therewith IE)! sending an electrical impulse during each period or cycle of movement, a receiving station having a lamp circuit which isenergized upon the reception of the impulse, a moving element at the receiving station, a lamp in said lamp circuit adapted to be energized upon the reception of the impulse, means to control the ight transmitted from the lamp in accordance with the departure of the second element from a synchronous phase relation with the first element, and means responsive to such control to synchronize the movement of said elements. 3. In apparatus of the class described, in combination, a sending station, a periodically moving element and means associated therewith for sending an electrical impulse during each period or cycle of movement, a receiving 36 station having an associated circuit which is energized upon the reception of the impulse, a moving element at the receiving station, a source 0 radiant energy in said circuit, a radiant energy reactive device cooperating w therewith, means to control the connecting energy link between the energy source and the energy reactive device in accordance with the departure of the second element from a synchronous phase relation with the first element, and means responsive to such control to synchronize the movement of said elements.

4. In apparatus of the class described, in combination, a sending station, a periodically 0 moving element and means associated therewith for sending an electrical impulse during each period or cycle of movement, a receiving station having an associated circuit which is energized upon the reception of the impulse, a periodically moving element at the receiving station, a light emitting device in said circuit and responsive to the reception of the impulse, a light reactive device cooperating with the light emitting device, means to control the connecting light link between the light emitting device and the light reactive device in accordance with a departure of the 1 second element from a synchronous phase relation with said first element, and means responsive to such control to synchronize the movement of said elements.

5. In an ap aratus of the character described, in com ination, periodically moving element, and means associated therewith for sending an electrical impulse during each period or cycle of movement, a receiving station havinrr an associated circuit which is responsive to t 1e reception of the impulse, a moving element at the receiving station adapted to be moved synchronously with said rst element, a light emitting means in said circuit, a light responsive means in operative relation thereto, means including said second element to vary the connecting light link between said light emitting and light responsive means in accordance with a departure of said second element from a synchronous relation with the first element, and means operative upon such variation to control the movement of said second element.

6. In apparatus of the class described, in combination, a sending station, a periodically moving element and means associated therewithforsendinganelectrical impulse during each period or cycle of movement, a receiving station having an associated circuit which is energized upon the reception of the impulse and a source of radiant energy therein, a moving element at the receiving station, means for imparting movement to said second element in substantial synchronism with said first named element, radiant energy responsive means cooperating with the source of radiant energy, means to control the energy link between the energy source and the energy responsive means in accordance with a departure of the second element from a synchronous phase relation with the first element, and means responsive to such control to increase or decrease automatically the rate of movement of said second element thereby to maintain the same in synchronism with the first element.

7. In an apparatus of the character described, in combination, a sending station, a eriodically moving element associated wit said sending station, means associated with said element and operative to transmit anelectricalimpulse from the sending station during each cycle of movement, a receiving station, a moving element adapted to be synchronized with said first moving element, a plurality of members of different light transmitting capacities associated with said second element, and means responsive to the reception of the impulse and including a light reactive device affected by said members to increase or decrease automatically the rate of movement of said second element.

8. In an apparatus of the character described, in combination, a rotatable member associated therewith, means associated with the rotatable element and operative at a fixed phase position of a sending station, I

a sending station, a

the element to transmit a periodic electrical impulse at each revolution thereof, a receiving station including an associated circuit which is energized upon the rece tion of the impulse, a rotatable element to e synchronized with said first element, a light emitting device in said circuit, a light reactive device cooperating therewith, means to control the connecting light link between the li ht emitting device and the light reactive evice in accordance with a departure of the second element from a synchronous phase relation with said first element, and means responsive to such control to increase or decrease automatically the rate of movement of the second element whereby synchronism thereof with the first element is obtained.

9. In an apparatus of the character described, in combination, a sendin station, a rotatable element associated t erewith, means associated with the element and operative at a fixed hase position of the element to send a perio ic electrical impulse at each revolution thereof, a receiving station, including an associated circuit which is energized upon the reception of the impulse, a rotatable element to be synchronized with said first element, a light emitting device in the circuit, the second element being provided with a plurality of members of different light transmitting ca acities, and means inclusive of a motor an a li ht reactive device in circuit therewith for increasing or decreasing the rate of rotation of said second element thereby to maintain the same in synchronism with the first member, the light reactive device being responsive to the light from the light emitting device passing thru said members to control the electrical conditions of the motor.

10. In apparatus of the character described. in combination, a periodically moving element, another periodically moving element whose rate of movement is to be synchronized with that of the first element, a source of radiant energy associated with the second element, a ra iant energ reactive device operatively disposed to sai source of energy and to said second element as to be responsive to the energy from said energy source, means to control such response in accordance with a departure of the second element from a synchronous relation with the first element, and means controlled by said energy reactive device for correcting the rate of movement of said second element, thereby to maintain such synchronous relation of the second element with the first element.

11. In apparatus of the character described, in combination, a periodically moving element, another periodically moving element whose rate of movement is to be synchronized with that of the first named element, driving means for the second element, a control circuit or said driving means, a

source of radiant energy associated with said second element, said second element being provided with means to control the transmission of radiant energy from the energy source therethru in accordance with a departure of said second element from the desired synchronous relation, and a radiant energy reactive device in said control circuit responsive to such transmitted energy and operative upon such response to correct the rate of movement of the driving means in accordance with such departure, thereby to maintain the synchronous relation of the second element with the first element.

12. The herein described method of synchronizin the periodicity of two disconnected re atively remote moving which consists in the steps of sending an electrical impulse during a period of movement of one of said elements, utilizing said impulse at a distance to control a radiant energy emitting member, directing the radiant energy emitted from said member to a radiant ener y reactive device, varying the response 0 the radiant energy reactive device to the energy directed thereto in accordance with a departure of the element to be synchronized from a synchronous phase relation with the said first named element, and controlling the rate of movement of the element to be synchronized in accordance with such response.

13. The herein described method of synchronizing the periodicity of two disconnected relatively remote removing elements which consists in the steps of sending an electrical impulse during a period of movement of one of said elements, utilizing said impulse at a distance to control a radiant energy emitting device, directing the energy emitted thru members of difierent ener transmitting capacities, and controlling t e rate of movement of the element to be synchronized in accordance with the radiant energy transmitted thru said members.

14. The herein described method of synchronizing two relatively remote moving elements which consists in the steps of sending an electrical impulse during each period or cycle of movement of one of said elements, utilizing said impulse at a distance to control a radiant energy emitting device, varying the transmission of energy from said emitting device in accordance with the rate of movement and phase position of the element to be synchronized, and controlling the rate of movement of said element to be synchronized thru such variation.

Signed at Washington this 9 day of J anuary, 1923.

HARRY J. NICHOLS.

elements CERTIFICATE OF CORRECTION.

Patent No. 1,759,864. Granted May 27, 1930, to

HARRY J. NICHOLS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 53, for "H" read "11''; page 4, line 100, claim 13, for "removing" read "moving"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of July, A. D. 1930.

Wm. A. Kinnan, (Seal) Acting Commissioner of Patents. 

